In the late Early Middle Ages, numerous Germanic petty kingdoms and chiefdoms were unified into three kingdoms, Denmark, Norway and Sweden, and Christianity was adopted, replacing Norse mythology, itself a subset of Germanic paganism. Scandinavia has, despite many wars over the years since the formation of the three kingdoms, been politically and culturally close. The constellations and alliances, however, have shifted over the centuries. For all of the 15th century, Scandinavia was united in the Kalmar Union. Today, the nations cooperate mainly in the European Union or the Nordic Council.The Danish, Norwegian, and Swedish languages form a dialect continuum and are known as the Scandinavian languages—all of which are considered mutually intelligible with each other. Faroese and Icelandic, sometimes referred to as insular Scandinavian languages, are only intelligible with continental Scandinavian languages to a very limited extent. Finnish and Sami languages are entirely unrelated to Scandinavian.The name Scandinavia historically referred vaguely to Scania. The terms Scandinavia and Scandinavian entered usage in the 18th century as terms for the three Scandinavian countries, their (Germanic) peoples and associated language and culture, being introduced by the early linguistic and cultural Scandinavist movement. The Scandinavian Peninsula subsequently also took its name from the ethno-cultural-linguistic term.[4]